Replication protein A (RPA) sumoylation positively influences the DNA damage checkpoint response in yeast
Replication protein A (RPA) sumoylation positively influences the DNA damage checkpoint response in yeast
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DOI：
10.1074/jbc.ra118.006006
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发表时间：
2019-02-22
影响因子：
4.8
通讯作者：
Zhao, Xiaolan
中科院分区：
文献类型：
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作者：
Dhingra, Nalini;Wei, Lei;Zhao, Xiaolan
DNA损伤反应依赖于蛋白质修饰，以引起应对遗传毒性条件所需的生理变化。除了典型的DNA损伤检查点介导的磷酸化，DNA损伤诱导的类小泛素化最近被证明可以促进遗传毒素的存活。这两种途径之间的串扰存在于酵母和人类细胞中。特别是，SUMO化是最佳检查点功能所必需的，但其潜在机制尚不清楚。为了解决这个问题，我们研究了苏莫化的第一个响应DNA损伤，ssDNA结合蛋白复合物复制蛋白A（RPA）在芽殖酵母（酿酒酵母）。我们划定的RPA大亚基，Rfa 1的基础上，以前和新的映射数据的SUMO化位点。使用类小泛素化缺陷型Rfa 1突变体的发现表明，Rfa 1类小泛素化与9-1-1检查点复合物平行作用，以增强DNA损伤检查点反应。从机制上讲，类小泛素化的Rfa 1促进了与检查点衔接蛋白Sgs 1的相互作用，并促进了检查点激酶的激活。我们的研究结果表明，基于SUMO的DNA损伤传感器的调制积极影响检查点响应。
The DNA damage response relies on protein modifications to elicit physiological changes required for coping with genotoxic conditions. Besides canonical DNA damage checkpoint-mediated phosphorylation, DNA damage-induced sumoylation has recently been shown to promote genotoxin survival. Cross-talk between these two pathways exists in both yeast and human cells. In particular, sumoylation is required for optimal checkpoint function, but the underlying mechanisms are not well-understood. To address this question, we examined the sumoylation of the first responder to DNA lesions, the ssDNA-binding protein complex replication protein A (RPA) in budding yeast (Saccharomyces cerevisiae). We delineated the sumoylation sites of the RPA large subunit, Rfa1 on the basis of previous and new mapping data. Findings using a sumoylation-defective Rfa1 mutant suggested that Rfa1 sumoylation acts in parallel with the 9-1-1 checkpoint complex to enhance the DNA damage checkpoint response. Mechanistically, sumoylated Rfa1 fostered an interaction with a checkpoint adaptor protein, Sgs1, and contributed to checkpoint kinase activation. Our results suggest that SUMO-based modulation of a DNA damage sensor positively influences the checkpoint response.